CAL4M1TY on 07 March 2009
Maybe your analog is problem/out of place.
If he's moving in one direction constantly, then thats the issue, otherwise you've got a messed up PSP/game.
If he's only moving in one direction, look up on google how to refix the analog into the original position (my friend did it once, it requires opening the case, but apparently it's easy).
